KR20140059705A

KR20140059705A - Heat sink for led lighting

Info

Publication number: KR20140059705A
Application number: KR1020130111017A
Authority: KR
Inventors: 하루유키 고니시; 하루유키 마츠다
Original assignee: 가부시키 가이샤 고베세이코쇼
Priority date: 2012-11-08
Filing date: 2013-09-16
Publication date: 2014-05-16
Also published as: KR101653028B1; CN106195949A; JP2014096254A; US9869463B2; US20140126225A1; CN103807831A; CN103807831B

Abstract

An object of the present invention is to provide a heat sink for an in-vehicle LED lamp capable of efficiently radiating heat.
A light emitting device comprising an LED element mounted on a substrate and integrally and continuously formed with a plate-like heat dissipating surface around the LED element, made of aluminum or an aluminum alloy having a specific heat conductivity?, And having a specific surface emissivity? The thermal resistance value R is set to a small value of 4.0 (K / W) by setting the total projected area of the respective heat radiation surfaces of the heat sink to be in the range of 19000 to 60000 mm 2 do. The projection areas P0 and P1 of two different directions of the plate-like heat radiation surfaces 10 and 11 of the heat sink are made sufficiently large with respect to the cross sectional area S of the substrate 2, Thereby improving the heat dissipation efficiency mainly using radiation.

Description

HEAT SINK FOR HEAD SINK FOR LED LIGHTING

The present invention relates to a heat sink for an LED lighting and a vehicle-mounted LED lamp for radiating heat generated in an LED lamp using a light emitting diode (LED) element as a light source in a surrounding space formed by a closed space, .

BACKGROUND ART [0002] Lighting using a light emitting diode (LED) element as a light emitting source is starting to penetrate the market gradually because of low power consumption and long life. Particularly, a vehicle-mounted LED lamp (automobile headlight, vehicle headlight) such as a headlight of an automobile has attracted attention in recent years, and replacement with an LED element has begun. In addition, with the application of this vehicle-mounted LED lamp (LED lighting), substitution with an LED lamp has started to be started in the embedded lighting of buildings and other fields.

However, there is a problem in that the LED element which is a light emitting element of the LED lamp is extremely weak to heat, and when the temperature exceeds a permissible temperature, for example, 100 占 폚, the light emitting efficiency is lowered or the lifetime is also affected. In order to solve this problem, it is necessary to dissipate heat generated during the light emission of the LED element to the surrounding space. Therefore, the LED lamp is provided with a large heat sink.

Conventionally, heat sinks for LED lamps (LED lamps) have been widely employed by aluminum die-casts or extruded materials made of aluminum (including aluminum alloys) (see Patent Documents 1 to 4). These conventional heat sinks generally include a substrate portion 30 in which an LED element (light source) L is placed and fixed on the front surface side as shown in a perspective view of FIG. 14, And a plurality of pin portions 40 arranged in parallel and projecting with an interval therebetween.

The structure of a lighting appliance (LED lamp unit) when these heat sinks for LED lamps are embedded in a vehicle-mounted LED lamp (automobile luminaire) is generally constructed by a front lens and a housing, And an LED serving as a light source is supported in the lamp room (see, for example, Patent Documents 5 and 6). 15, the lamp unit 51 for a vehicle includes a lamp chamber 54 formed by a front lens 52 and a housing 53, and a lamp unit 54 is provided in the lamp chamber 54. [ The unit 55 is supported.

The optical system includes an LED element (light source) 56, a mount plate 57 on which the mounting substrate of the LED element 56 is mounted, and a mount plate 57 A reflector 58 connected to the reflector 58, a lens holder 59 connected to the reflector 58, a shield 60 extending upward from the bottom surface of the lens holder 59, and a lens holder 59, And a projection lens 61 that is supported on the base plate 61, and forms a projector lamp.

The heat dissipation system includes a mount plate 57 on which a mounting substrate of the LED element 56 is mounted, a heat sink 62 fixed to the mount plate (substrate 57), and a mount plate 57 and a heat sink And a reflector 58 connected to the heat dissipating member 63 in which the heat dissipating members 62 are integrated. The substrate 57, the heat sink 62, and the reflector 58 are all made of any one of Al, Al alloy, Cu, and Cu alloy.

Next, when the LED element (light source) 56 is turned on and emits light, light from the LED element 56 to the light reflection surface 64 of the reflector 58 is reflected by the light reflection surface 64 And is directed toward the front projection lens 61, and a part of the light path is blocked by the shield 60. On the other hand, among the light reflected by the light reflection surface 64 of the reflector 58, the light that is not blocked by the shield 60 is guided into the lens holder 59 to reach the projection lens 61, And is irradiated forward of the vehicle LED lamp 51 through the front lens 52 of the vehicle.

Further, regarding the heat in the heat dissipation system, when the LED element 56 is turned on, light is emitted as well as heat is generated. Thus, the heat (self-heating) generated in the LED element 56 is transferred to a substrate (not shown) on which the LED element 56 is mounted, and is conducted to the mount plate 57 Move. Then, the heat conducted on the mount plate 57 is transferred to the heat sink 62 fixed to the mount plate 57. The heat reaches the surface of the heat sink 62 by the heat sink 62 and conducts in the heat sink 62. The heat is transferred to the air in the vicinity of the surface and moves, And is dissipated out of the sink 62.

Patent Document 1: Japanese Patent Application Laid-Open No. 2007-193960 Patent Document 2: JP-A-2008-7558 Patent Document 3: Japanese Patent Application Laid-Open No. 2009-277535 Patent Document 4: JP-A-2010-278350 Patent Document 5: JP-A-2008-130232 Patent Document 6: JP-A-2009-76377

However, when such a heat sink is incorporated in a housing as a vehicle-mounted light such as a headlight of an automobile or a tail lamp, it is inevitably installed and used in a limited narrow space or a closed space as shown in Fig. 15 . In a narrow space or a closed space of the vehicle-mounted lighting-use housing, the heat radiation space is also limited to a small extent, and in Fig. 14, the heat radiation area in the vicinity of the base portion 30 of the conventional heat sink and the fin portion 40 (Volume) becomes smaller, so that there is almost no air convection. Under such use environment, heat radiation effect due to convection of air can hardly be expected, and heat radiation by radiation is required.

However, in the conventional heat sink, as shown in Fig. 14, the convexity of the air from the heat radiating face, which increases the area of the heat radiating face of the fin portion 40 and the heat sink 62 of Fig. 15 And the heat radiation due to the radiation is not considered. Therefore, the conventional heat sink necessarily has a problem in that heat radiation due to the radiation is insufficient, and efficient heat radiation can not be achieved in a narrow space or a closed space of a lighting-use housing for a vehicle.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an LED lighting heat sink capable of efficiently radiating heat by radiation. In other words, it is an object of the present invention to provide a heat sink for LED lighting that can efficiently dissipate heat from the LED light source to the radiation main body even when the air is not convected or installed in a small closed space.

In order to achieve the above object, the heat sink for LED lighting according to the present invention is characterized in that an LED element is attached to one of the front and back surfaces of a substrate, and a plate- Wherein the substrate and the plate-like heat dissipation surface are made of aluminum or an aluminum alloy having a heat conductivity? Of 120 W / (m 占 K) or more and a surface emissivity? Of the substrate and the plate- A heat sink comprising: a heat sink having a plate thickness of 0.8 to 6 mm between the substrate and the plate-shaped heat dissipating surface, The sum of the areas is set in the range of 19000 to 60000 mm < 2 >. The present invention provides a heat sink for LED lighting capable of efficiently dissipating heat from the LED light source to the radiation main body even when it is installed in a closed space in which there is no air convection or a small amount of air can not be expected .

In the present invention, after defining the heat conductivity? Of the LED lighting heat sink made of aluminum or an aluminum alloy and the surface emissivity? Of each heat dissipation surface as described above, the thickness of each heat dissipation surface of the heat sink and the angle And defines the total value of the projected areas. This is because, in a heat sink made of aluminum or an aluminum alloy, the sum of the plate thickness and the projected area in the three-dimensional space of each heat radiation surface (total projected area) largely affects radiation by radiation. In the present invention, the heat resistance of the heat sink is selected as an index (reference) for evaluating the heat radiation due to the radiation. The heat resistance of this heat sink shows a heat radiation performance mainly based on the radiation of the heat sink. The smaller the value of the heat resistance value R of the heat sink, the higher the heat radiation efficiency with radiation as a main component. In addition, the heat sink for LED lighting according to the present invention is a heat sink having a plate-like heat radiation surface integrally and continuously provided on a side surface of a substrate on which an LED element is mounted, The projected areas of the two different directions are respectively projected by the parallel light beams irradiated from the direction perpendicular to the plate-like heat-radiating surface, passing through the attachment position of the LED element, And satisfies P? 8 占 S for each cross-sectional area S of the substrate which is a parallel cross-section. Here, the fact that the projected area P of the plate-like heat-radiating surface in two different directions satisfies P? 8 占 S means that only the plate-like heat-radiating surface in two different directions satisfying this relationship , It means that even if the plate-like heat-radiating surface which does not satisfy this condition is different, this is allowed. As described above, in the present invention, the projected area P of the plate-like heat radiation surface in the two different directions of the heat sink for LED lighting is set to a predetermined size or larger in relation to the sectional area S of the substrate. In a heat sink of a three-dimensional type in which a plate-shaped heat-radiating surface with the substrate as a reference is integrally and continuously formed on the side surface of the substrate, there is no convection caused by air such as a lamp- , The projected area of the plate-shaped heat radiation surface greatly affects the heat radiation due to radiation, which is a unique problem due to the rise of the shape of the heat radiation surface and the solid shape.

According to the present invention, the plate thickness range of the heat sink made of aluminum or the aluminum alloy and the total projected area of the heat dissipation surface are defined, and the heat radiation efficiency with radiation as a main body is remarkably improved, Can be made small. Therefore, a heat sink for LED lighting, in particular, a vehicle LED light fixture, which eliminates the waste of material aluminum or aluminum alloy, minimizes material usage, enables miniaturization and thinning of the heat sink, .

When the thermal resistance value R of the heat sink is used, the total projected area of the substrate and the plate-like heat dissipating surface, and the total projected area of the heat dissipating surface, Further, the surface area of the heat releasing surface can be obtained. This facilitates the design of the heat sink. Further, it is possible to easily design the size and shape of the heat sink, the number of heat radiating surfaces and the arrangement of the heat radiating surfaces, which significantly improves the heat radiating efficiency with radiation as a main body. In other words, it is also possible to provide a method of designing a heat sink in which the radiation efficiency is radically improved.

1 is an explanatory diagram showing the relationship between the thermal resistance value R and the total projected area of the heat sink plate thickness and the respective heat radiation surfaces in the case of the emissivity of 0.8 on the heat radiation surface.
2 is a perspective view showing an embodiment of a heat sink according to the present invention;
3 is a perspective view showing another embodiment of a heat sink according to the present invention;
4 is a perspective view showing another embodiment of a heat sink according to the present invention;
5 is a perspective view showing another embodiment of a heat sink according to the present invention.
6 is a perspective view showing another embodiment of the heat sink according to the present invention;
7 is a perspective view showing another embodiment of a heat sink according to the present invention;
8 is a perspective view showing another embodiment of the heat sink according to the present invention.
9 is a perspective view showing another embodiment of the heat sink according to the present invention.
10 is a perspective view showing another embodiment of a heat sink according to the present invention;
11 is a perspective view showing another embodiment of a heat sink according to the present invention.
12 is a perspective view showing another embodiment of the heat sink according to the present invention.
13 is a perspective view showing another embodiment of a heat sink according to a comparative example;
14 is a perspective view showing an example of a conventional heat sink.
15 is a sectional view showing an example of a vehicle mounted LED lamp having a conventional heat sink.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

The basic structure of the heatsink:

2 to 12, a preferred form of the basic structure of the heat sink 1 according to the present invention for efficiently dissipating heat from the LED element light source to the radiation main body will be described first.

2 to 12, the heat sink 1 according to the present invention is characterized in that the LED element 9 is attached (mounted) to one of the surfaces 3 and 4 of the front and back surfaces of the substrate 2, Like heat radiating fins 10 to 17 including a surface 3 and 4 of the front and back sides of the substrate 2 itself around the LED element mounting surface 9, As shown in FIG. The heat dissipation surface or the heat dissipation surface (heat dissipation surface area) of the plate 2 in the substrate 2 or the heat dissipation fins 10 to 17 is set to be equal to or greater than the heat dissipation surface (Surface area) of each of the four peripheries in the thickness direction of each of the four peripheries, as well as the front and back surfaces (front and rear surface areas).

In the following description, a flat plate-like heat dissipation fin and a flat plate-like heat dissipation surface of the heat dissipation fin are sometimes referred to by the same numerals for the sake of convenience.

2 to 12 commonly have a flat plate-like substrate 2 having a rectangular shape (rectangular shape) as seen from the plane where the LED elements are attached. The substrate 2 has two front and back surfaces in the Y direction (vertical direction) side of each drawing, and these surfaces extend in the X and Z directions in the respective drawings. 1 to 7, the upper surface of each of the figures is referred to as an LED element 9 for the sake of convenience, and the surface of the flat plate- And is attached to the center of the plane. The lower surface of each drawing is also referred to as the back surface (4) for convenience.

The top and bottom surfaces 3 and 4 of the substrate 2 are orthogonal to one or both surfaces (the extending direction of the surface = orthogonal to the X and Z directions of the respective drawings) Shaped heat radiating fins 10 to 17 which protrude and extend in a direction perpendicular to the longitudinal direction. These plate-like heat dissipation fins 10 to 17 are provided on the front and back surfaces 3 and 4 of the substrate 2 so as to face outward. However, as shown in Figs. 1 to 7, , 4) need not be orthogonal to the plate-shaped heat-radiating fins at an angle of 90 degrees. For example, the heat dissipation fins may be provided at an angle of less than 90 degrees or more than 90 degrees and inclined outward with respect to the front and back surfaces 3 and 4 of the substrate 2. [

However, in any case, these flat plate-shaped heat dissipation fins 10 to 17 are formed integrally and continuously with the substrate 2 in a continuous manner. That is, at least planar top and bottom surfaces of the flat plate-like heat dissipation fins 10 to 17 are formed on the surfaces 3 and 4 of the substrate 2 together with the surface of each side surface in the thickness direction 4, 5, 6, 7, 8 in the thickness direction in the circumferential direction of the base plate 4, without being interrupted. That is, it has a heat radiating surface facing in any three-dimensional directions of X, Y, and Z.

Therefore, the heat from the LED element 9 passes through the surface (surface) 3 of the substrate 2 on the side where the LED element is attached, to the rear surface 4, A continuous heat transfer surface which is successively transferred to the surface of the substrate W is formed. Further, a continuous heat radiating surface for radiating heat continuously from these continuous heat transfer surfaces is also formed.

The shape of the substrate 2 is exemplified by a planar shape or a planar shape of a rectangle (quadrangular) in plan view in Figs. 2 to 12. However, the shape of the substrate 2 may be a planar shape such as a circular shape, a triangular shape, a polygonal shape, an irregular shape, or the like in plan view or an S shape, a V shape, a U shape A three-dimensional shape such as a cylindrical shape, a prismatic shape, a step, a concavo-convex, a notch, a slit, or the like can be appropriately selected.

2 to 12, the LED element 9 is attached (mounted) to the central portion of the front surface 3 of the substrate 2, but the attachment position thereof can be freely selected according to the design.

2 to 12, the flat heat dissipation fins 10 to 17 are orthogonal to the flat surfaces (planes) 3 and 4 of the substrate 2 extending in the horizontal direction at an angle of 90 degrees. It is to be noted that the flat plate heat dissipation fins 10 to 17 are necessarily orthogonal to the flat surfaces 3 and 4 of the substrate 2 which can not be extended in the horizontal direction at an angle of 90 degrees, It is not necessary to set the same installation angle. That is, the heat sink 1 may be installed larger than 90 degrees or smaller than 90 degrees depending on the use and design of the heat sink 1.

Thermal conductivity of aluminum λ:

In order to enhance the heat dissipation efficiency of the radiation main body of the heat sink 1 in the present invention, the thermal conductivity λ of the heat sink 1 made of aluminum or an aluminum alloy and the surface emissivity ε . In other words, the thermal conductivity? Of the substrate 2 and the plate-shaped heat radiation surfaces 10 to 17 constituting the heat sink 1 and the surface emissivity? Of each heat dissipation surface are defined.

The heat conductivity lambda of the aluminum or aluminum alloy constituting the heat sink 1 is 120 W / (m · K) or more, and preferably 140 W / (m · K) or more. The heat from the LED element 9 is transmitted through the surface (surface) 3 of the substrate 2 on the side where the LED element is attached, as described above, as the structure of the heat sink 1, A high heat radiation performance can not be achieved even if a continuous heat transfer surface continuously formed on the back surface 4 or the peripheral side surface of each heat dissipation fin or the surface in the thickness direction is formed.

The unit of W / (m · K) of the thermal conductivity λ means that when there is a temperature gradient of 1 degree per meter, one joule of heat travels over a section of 1 square meter for one second. The thermal conductivity of a representative metal at 27 캜 is as follows: copper: 402, aluminum: 237, stainless steel (18% Cr, Ni 9%, C 0.05% , And Zn 30%): 119.

When the heat sink 1 is made of aluminum or an aluminum alloy general material such as a cast material, a cold rolled plate material (rolled plate material) or an extruded shape material, the heat conductivity lambda is set to 120 W / (mK) / (m · K) or more. From this point of view, the aluminum die-cast is inadequate because the thermal conductivity? Is about 80 W / (m 占 로부터) due to the main composition and the thermal conductivity can not be achieved. The aluminum alloy species to be used is preferably a composition within the JIS standard, or a pure aluminum which is a composition corresponding to this specification, from the viewpoint of achieving a high thermal conductivity. However, from the viewpoints of improvement in formability and workability of heat sink, improvement of strength and rigidity, various aluminum alloys, which are compositions according to JIS standards and compositions corresponding to this standard, It is possible to utilize the high strength characteristics.

Surface emissivity at each open surface ε:

In order to increase the heat radiation efficiency of the radiation main body of the heat sink 1 (in order to obtain a high heat radiation property of the heat sink 1), the heat sink 1, that is, It is preferable that the surface emissivity? Of each of the heat dissipating surfaces of the substrate 2 and the plate-like heat dissipating surfaces 10 to 17 constituting the sink 1 is high. The higher the surface emissivity epsilon, the greater the amount of heat transferred by radiation as a heat sink. In this respect, the surface emissivity? Is not less than 0.65, more preferably not less than 0.80.

The emissivity? Is a ratio to a theoretical value of a thermal radiation of an actual object (thermal radiation of an ideal blackbody, which is a thermal body), and may be an actual measurement, a method described in Japanese Patent Application Laid-Open No. 2002-234460, Or may be measured by a measuring apparatus.

When the heat sink 1 of the present invention is made of aluminum (pure aluminum) or an aluminum alloy, the surface emissivity? Remains at a relatively low value. However, in order to set the surface emissivity? To a high value of 0.65 or more, and more preferably 0.80 or more, it is preferable that the surface of each of the heat dissipation surfaces of the substrate and the plate-like heat dissipation surface is coated with a coating material such as black, A precoating treatment (coating film) may be carried out. This pre-coating treatment is also performed on the thin metal plate of the material before pressing, and also serves as a lubricant in the pressing process. After molding into a predetermined shape, after coating such as electrodeposition coating or spray coating, an alumite treatment, or the like may be performed.

Projected area:

Hereinafter, the significance of the projected area of the heat sink specified by the present invention will be described in relation to the thermal resistance value R.

Fig. 1 shows the relationship between the plate thickness of the heat sink, the total projected area of the respective heat radiating surfaces, and the thermal resistance value R. Fig. In Fig. 1, the heat resistance value R (experimentally measured) in the case where the surface emissivity of the heat radiation surface of the heat sink is 0.80 is expressed by the thickness of the heat sink (transverse axis: And the total projected area (longitudinal axis: unit of step is expressed in m2).

Fig. 1 is an example of the heat sink 1 of Fig. 8, which will be described later. After variously changing the plate thickness of the heat sink 1 of Fig. 8 and the total projected area of each heat radiating surface, And the element 9 are mounted under a common condition. Then, the difference between the temperature T of the LED element 9 and the ambient temperature T0 at the time of the normal light emission is measured and divided by the power consumption W of the LED (in the above formula) And the thermal resistance value R, respectively, and these are represented by contour lines, respectively.

In Fig. 1, the thickness of the heat sink 1 of Fig. 8 is varied in the range of 0.3 mm to 10 mm. The total size (total area) of the top and bottom surfaces 3 and 4 and the heat radiation surfaces of the plate-like heat radiation surfaces 10 and 11 of the substrate 2 is set so that the total projected area of the heat sink is 5000 to 300000 mm & Range.

1, the aluminum constituting the heat sink 1 is JIS1050. At this time, the thermal conductivity? Was 231 W / (mK). The surface emissivity epsilon of the heat sink 1 (the substrate 2 and the plate-like heat radiation surfaces 10 and 11) was measured by using an electrodeposited coating of a commercially available black cationic resin film, As a result of measurement with one commercially available portable emissometer, all portions were the same O.83. The mounted LED element 9 has a power consumption of 13W. Then, the test body made of LED and heat sink was housed in a wooden box of 300 x 300 x 300 mm which simulated the closed space of the vehicle-mounted LED lamp, and the above heat radiation test was performed.

The plate thickness of the abscissa in Fig. 1 is the plate thickness of the plate-like heat dissipation surfaces 10 and 11 of the substrate 2 and the heat dissipation fins having the same plate thickness. The total projected area of the heat radiating surface of the longitudinal axis in Fig. 1 is the total projected area of the X and Y of Fig. 18, which is composed of the front and back surfaces 3 and 4 of the substrate 2 and the four plate- And the projected areas are parallel to the X, Y, and Z axes, respectively, with respect to each plane perpendicular to the Z axis. That is, the sum of the projected areas of the three directions in the X, Y, and Z directions, respectively.

Incidentally, this is the total projected area including the projected area portions formed by the respective surfaces (upper surface, lower surface, both end surface) in the plate thickness direction of each of the heat radiating fins 10, 11. 8, since the respective side surfaces in the plate thickness direction around the periphery of the substrate 2 are integrated with the respective heat dissipation fins, the projected areas of the respective side surfaces in the thickness direction of the heat dissipation fins 10, Respectively, in the projected area of the plate-shaped heat-radiating surface.

1, the area surrounded by the lower square is defined as the sum of the plate thickness of the heat sink specified in the present invention and the total heat dissipation surface It is the range of projection area. The area enclosed by the larger square is an area in which the total projected area of each heat radiating surface of the heat sink is set in the range of 19000 to 60000 mm 2 after the thickness of the heat sink is set in the range of 0.8 to 6 mm. The area surrounded by the smaller square is a preferable area where the total projected area of the heat sink is set to 19000 to 50000 mm 2 after the plate thickness of the heat sink is set within the range of 0.8 to 4.0 mm.

The plate thickness of the heat sink 1 and the total projected area of the respective heat radiating surfaces are well correlated with the thermal resistance value R, which is an index indicating the heat radiation efficiency of the heat sink. That is, the plate thicknesses of the substrate 2 and the plate-like heat dissipation planes (flat plate heat dissipation fins) 10 to 17 constituting the heat sink 1, the total projected area of these respective heat dissipation planes, Are well correlated.

This heat resistance value R is an index (reference) for evaluation of the radiation heat radiation property of the heat sink 1 made of aluminum or an aluminum alloy, and the smaller the value of the heat resistance value R of the heat sink 1 , The heat dissipation efficiency mainly using radiation is increased.

Further, when the specification (requirement) of the heat radiation performance according to the use of the heat sink is given as the heat resistance value R of the heat sink, the necessary (optimum) plate thickness of the substrate and the plate- Or the required surface area of the heat-radiating surface can be obtained. For this reason, it is easy to design a heat sink that is made lightweight by minimizing the amount of aluminum or aluminum alloy used. In addition, the size and shape of the substrate or the plate-like heat dissipating surface of the heat sink, the shape of the plate-like heat dissipation surface of the heat sink, It becomes easy to design the structure such as the number of open surfaces and the arrangement of the substrate or the LED element. In other words, it is also possible to provide a method for designing a heat sink in which heat radiation efficiency, which is mainly composed of radiation, is remarkably improved in a closed space such as an LED lamp mounted on a vehicle.

In the present invention, the plate-thickness range of the heat sink 1 (the substrate 2 and the plate-shaped heat-radiating surfaces 10 to 17) made of aluminum or an aluminum alloy and the total projected area of each heat- The thermal resistance value R of the heat sink 1 is reduced to be 4.0 K / W or less as shown in FIG. 1, thereby significantly improving the heat radiation efficiency with radiation as a main component.

However, it can be seen that it is difficult to make the thermal resistance value R smaller than 1.0 K / W from the region surrounded by the square in FIG. 1 of the present invention. This is due to the structural limitations of providing a heat sink for the heat sink, which must accommodate the heat sink in a finite space such as a mechanical limit of aluminum or an aluminum alloy or a head lamp of an automobile. Therefore, the practical lower limit value of the thermal resistance value R of the heat sink 1 made of aluminum or an aluminum alloy is 1.0 K / W. Therefore, the preferable range of the heat resistance value R of the heat sink 1 is 4.0 K / W or less and 1.0 K / W or more.

When the heat resistance value R of the heat sink 1 exceeds 4.0K / W, 5.0K / W, and 6.0K / W in FIG. 1, cooling of the LED by the heat sink is not good, Resulting in a decrease in luminance or a reduction in the lifetime of the device. In addition, it is impossible to provide a lightweight heat sink in which the waste of the materials used and the waste of the structure are omitted.

Total Projected Area:

In the present invention, on the premise of the basic structure of the above-mentioned heat sink, the heat conductivity?, And the thickness of a sheet to be described later, heat radiation efficiency of the radiation main body is increased and the heat resistance value R of the heat sink 1 is set to 4.0K / . Therefore, as the sum of the projected areas for the three planes perpendicular to each other in the three-dimensional space of the heat sink, the respective planes perpendicular to the X, Y and Z axes of the heat sink are parallel to the X, Y and Z axes (Total projected area) of each projected area when projected with one parallel light beam is defined. The total projected area is set to 19000 mm 2 or more.

Here, the projected area of each of the above-mentioned heat radiation surfaces is a projected area of each heat radiation surface, which is projected by the parallel rays irradiated from the direction perpendicular to each heat radiation surface as described above. The projected area defined in the present invention is a heat radiation area in the case where the heat radiation surface most efficiently radiates heat, and is most suitable as an index most suitably expressing the effect (influence) of the heat radiation area on the heat radiation surface.

As shown in FIG. 1, the larger the total projected area of the heat sink, the higher the heat radiation efficiency of the radiation main body and the smaller the thermal resistance value R. This is because the total projected area of the heat sink greatly influences the heat resistance of the heat sink 1 according to the present invention, because heat radiation due to radiation is influenced by the size effect. The larger the total projected area of the heat dissipating surfaces of the substrate and the plate-like heat dissipating surface, the higher the heat dissipation efficiency of the radiation is, and the smaller the value of the heat resistance value R of the heat sink.

Therefore, the heat from the LED element 9 passes through the surface (surface) 3 of the substrate 2 on the side where the LED element is attached, to the side surface around the back surface 4 and each heat- The heat transfer amount can be expected as the total projected area (larger size) of the heat dissipation surfaces of the substrate and the plate-like heat dissipation surface becomes larger (larger size) .

The sum of the projected areas of the three-dimensional space of the heat sink 1 with respect to three mutually orthogonal planes (total projected area) is not limited to the above-described FIG. 8, The heat sink 1 having the top and bottom surfaces 3 and 4 and the respective heat dissipation surfaces of the heat dissipation fins 10 to 17 is formed so that X, Y, and Z axes, respectively, of the respective projected areas. That is, the sum of the projected areas of the heat sink 1 in the three directions, that is, in the X, Y, and Z directions, respectively.

6, 7, and 8 (5 on the left side of the drawing, 6 on the lower side of the drawing, 7 on the right side of the drawing, and 8 on the left side of the drawing) The upper side of the drawing) also becomes the emission surface of the heat, so that the total projected area thereof is also added. In addition, the surfaces (upper surface, both end surfaces) of the respective heat radiating fins 10 and 11 in the thickness direction (thickness direction) are likewise the emission surfaces of the upper surface and both end surface heat rows. Therefore, Is added to the projection area.

Because of this definition, the specified total projected area is the projected area of the heat sink which does not depend on the attachment (mounting) area of the LED element 9 (including the area excluding the area) The projected area is the sum of the open faces (10 to 17).

If the total projected area of each of the heat dissipation surfaces is too small, the radiation efficiency of the radiation can not be made high, and the heat resistance value R becomes too large. However, In applications where space is limited, there is a limit to the upper limit of the size itself. In addition, it is important that the larger the size, the heavier the weight becomes.

Therefore, the total projected area of the respective heat-radiating surfaces of the substrate and the plate-shaped heat-radiating fins is set to be not more than 60000 mm 2, preferably not more than 50000 mm 2, and the range of 19000 to 60000 mm 2, .

Thermal resistance value R:

The heat resistance value R in the present invention is a value obtained by dividing the difference DELTA T (T-T0) between the temperature T at the normal time of the LED element 9 and the ambient temperature T0 around the heat sink 1, Is a value of (T-T0) / W divided by the power consumption W and is a value that can be obtained by actual measurement as described with reference to Fig. The original thermal resistance value defined in electrothermal engineering is (T-T0) / Q obtained by dividing the difference ΔT = (T-T0) between the normal temperature T of the heat source and the ambient temperature T0 by the heating value Q of the heat source. Strictly speaking, the heating value Q of the heat source is different from the power consumption W of the LED. However, since the luminous efficiency of a typical LED is 10% or less and most electric energy is converted into heat, the above definition is used.

Here, in the heat sink 1, the temperature T at the normal time during the normal light emission operation of the LED element 9 or during normal light emission is highest than other portions around the LED element 9, though it is self-evident. The temperature of the other portions around the LED elements 9 is determined by the fact that the temperature T at the normal time of the LED element 9 is determined by actual measurements and actual results The temperature distribution in which the temperature is lowered in a substantially concentric circle shape on the front and back surfaces of the surrounding substrate 2 and the heat radiation surfaces 10 to 17 around the LED element 9 As shown in Fig.

Plate thickness of board and heat sink fins:

In order to increase the heat radiation efficiency of the radiation main body of the heat sink and to set the heat resistance value R to 4.0 K / W or less on the premise of the above-described basic structure of the heat sink or the heat conductivity? The thickness of the heat dissipation fins 2 and the heat dissipation fins 10 to 17 is in the range of 0.8 to 6.0 mm, preferably 0.8 to 4.0 mm.

As shown in Fig. 1, the larger the plate thickness (the thicker the plate thickness), the smaller the thermal resistance value R, and the higher the radiation efficiency of the spinneret is. This is because the larger the plate thickness (the thicker the plate thickness), the larger the amount of heat conduction. Therefore, the heat from the LED element 9 passes through the surface (surface) 3 of the substrate 2 on the side where the LED element is attached, to the side surface around the back surface 4 and each heat- A high heat conductivity such as a large size substrate and a plate-like heat dissipating surface can be expected, as long as the structure of the heat sink 1 has a continuous heat transfer surface continuously transferred to the heat sink 1.

From Fig. 1, it is proved that the plate thickness of the substrate and the plate-like heat dissipating surface is set to 0.8 mm or more in order to obtain a heat radiation efficiency of the radiation main body while setting the heat resistance value R to 4.0 K / W or less. If these plate thicknesses are too small (thin), heat dissipation mainly using the radiation is not sufficiently generated, and the thermal resistance value R becomes too large.

However, in applications such as vehicle-mounted LED lamps where lightness is required and space for installation is limited, there is a limit to the upper limit of its size and plate thickness. Therefore, the plate thickness of the substrate and the plate-shaped heat-radiating surface is set to 6 mm or less, preferably 4.0 mm or less, and the thickness in the range of 0.7 to 6 mm, preferably 0.8 to 4.0 mm .

The thickness of each plate of the substrate and the heat-radiating fin may be varied, if they are all the same or within the above-mentioned specified range or preferable range.

Preferable shape of the heat radiating fin:

In order to achieve the above-described performance of the heat sink according to the present invention, various preferred embodiments thereof are preferable in the structure (arrangement) of the plate-like heat radiation fins 10 to 17 as the plate- 12 will be described below. In the heat sink 1 according to the present invention shown in Figs. 2 to 12, the housing for lighting on the vehicle is mainly provided with heat radiation by radiation, which is required in a narrow space or in a closed space, The structure and arrangement method of the heat dissipation fin to improve the efficiency are studied.

First, the heat sink 1 according to the present invention shown in Figs. 2 to 12 assumes the basic structure of the above-described heat sink, and the heat dissipation fins 10 to 17, Are formed continuously and integrally with the surfaces 3 and 4 of the substrate 2 in a total of 2 to 8 sheets provided on the two surfaces 3 and 4 of the substrate 2, respectively. Such a shape can be produced by machining an extruded bar material, bending the rolled plate material, casting, etc. with aluminum of a material.

The number of fins extending parallel to each other and extending in the same direction among the heat dissipation fins 10 to 17 is set so that the number of fins extending in the same direction is set to any one of cross sections perpendicular to the two surfaces 3, It is supposed that the number is two or less. That is, the thickness of the heat sink 1 is not more than two at any end face of the heat sink 1, which is cut in an arbitrary direction orthogonal to the two faces 3 and 4 of the substrate 2. [

Meaning of the extension direction of the heat dissipation pin:

Here, the term " extending in the same direction " in the present invention means a parallel state naturally, but it does not mean only parallel in a strict sense, and the term " extending in the same direction " May be slightly different. It is an object of the present invention to avoid excessive overlapping of the heat dissipation fins in any direction in the three-dimensional direction of the heat sink, and to obtain high heat radiation efficiency without waste of material. Therefore, even if there is a slight difference in the angle in the extending direction of the flat plate side surfaces of the heat radiation fins with each other within a range that does not hinder the purpose or effect, it can be seen that they extend toward the same direction. Even if there is a slight difference in the angle of extension of the side surfaces of the heat radiating fins with respect to each other, or even if they are strictly parallel and there is no difference in the angle, as shown in Fig. 14, Because there is no big difference in how they overlap each other.

It is considered that the heat radiation fins extend toward the same direction when the angle formed by the extending direction of the flat plate side surfaces of the heat radiation fins with respect to the reference of the difference in angle is 30 degrees or less. Conversely, if the angle formed by the extending direction of the flat plate side surfaces of the heat radiation fins exceeds 30 degrees, it is not considered that the heat radiation fins extend toward each other in the same direction.

2 to 7 to be described later, two heat-radiating fins are arranged in parallel to each other in a shape extending in the same direction with the LED element 9 interposed therebetween, and a rectangle And the adjacent heat radiating fins are arranged orthogonally (intersecting at right angles) with each other. However, the present invention is not limited to such an arrangement, but may be a circular shape or an arc shape with the LED element 9 as a center point, surrounding the LED element 9, for example, in the form of a domino, The heat radiating fins may be arranged with intervals while changing angles sequentially.

The number of heat dissipation fins extending in the same direction as each other is set so that the number of the heat dissipation fins can be increased in any cross section orthogonal to the two surfaces 3 and 4 of the substrate 2 ) Is defined as "to prevent excessively overlapping of the heat radiation fins with respect to an arbitrary direction in the three-dimensional space. As will be described later, there is a case in which even a single heat sink pin has a plurality of flat plate-like heat dissipating surfaces (heat dissipating side surfaces) extending in different directions, such as L-shaped or co-shaped Japanese . Not only the heat radiation fins in a flat plate shape but also the heat radiation fins having a shape having a plurality of heat radiation surfaces in different extending directions or shapes may be formed in such a manner that the straight line sections forming the L- And the number of sheets in the same direction (overlapping state) is examined. According to this view, the number of the heat-radiating fins extending in the same direction in any cross-section orthogonal to either one of the front and back surfaces of the substrate is made equal to or less than two, so that the heat-radiating fins or the heat- Can be avoided. That is, the above-mentioned rule refers to the number of heat dissipation fins of the heat dissipation fin as the number of heat dissipation fins (heat dissipation side) of the heat dissipation fins as the number of heat dissipation fins, So that excessive duplication is avoided, irrespective of the position, so that the above-mentioned two or less stipulations are satisfied.

In this regard, when the number of the heat radiating fins extending in the same direction as each other is defined as "not more than 2 pieces on any one of the surfaces 3, 4 of the substrate 2" The absolute number of heat dissipation fins is defined. Therefore, excessive overlapping may occur depending on the positions of the two surfaces 3 and 4 of the substrate 2, without regard to the number of fins of the heat radiation surface in the different directions of the heat radiation fins such as the L shape or the U shape There is a possibility of occurrence. Therefore, it is defined as "no more than two pieces" at any cross section orthogonal to the two surfaces 3, 4 of the substrate 2 (any cross section of the heat sink cut in this cross section).

2 to 12 exemplify the shape of the whole shape or the flat plate side in the shape of a rectangle (square). However, the shape of the heat dissipation fins 10 to 17 is not limited to this rectangle, Dimensional shape can be selected. For example, when a plurality of the heat radiating fins 10, 11 or the heat radiating fins (12, 13) of a flat plate shape are extended in different directions (for example, 90 degrees or more) It may be a U-shape in which the heat radiating fins 10, 11, and 10 or the heat radiating fins 12, 13, and 12 are integrally formed. (Heat radiating side), or an arc-shaped or curved radiating surface (radiating side surface) or an entire shape, as long as they can be manufactured. Further, the shape or thickness of the outwardly facing plate thickness section may be different in L shape or step shape at the height position. It is also possible to appropriately select a surface shape such as a circular shape, a triangular shape, a polygonal shape, or an amorphous shape on the heat radiating surface.

2:

The heat dissipation fins 10 and 11 of the flat plate shape of Fig. 2 are arranged in such a manner that a total of four pieces of heat dissipation fins 10 and 11 on the side of the LED element mounting surface 3 supporting the LED element 9 of the substrate 2, And the side surfaces of the flat plate shape are integrally and continuously provided. The heat dissipation fin is not provided on the other side of the back surface 4, but only the flat back surface 4 exists. The extension lengths (widths) of the heat dissipation fins 10 and 11 on the substrate 2 are set to be larger than the lengths (widths) of the sides 5, 6, 7 and 8 of the rectangular substrate 2 short.

The heat dissipation fins 10 and 11 provided on the side of the LED element attachment face 3 are arranged symmetrically with respect to the heat dissipation fins 10 and 10 on the left and right sides of the drawing, The upper and lower heat radiating fins 11 and 11 extend in the same direction and are arranged in parallel with each other. That is, the heat dissipation fins 10, 10 and the heat dissipation fins 11, 11 mutually opposed to each other are arranged on the surface side of the LED element attachment face 3 at a position sandwiching the LED element 9 in the middle As shown in Fig. The number of fins extending in the same direction among these heat dissipation fins 10 and 11 is set so that the number of fins extending in the direction perpendicular to the surfaces 3 and 4 of the substrate 2 The heat sink 1 is formed of two pieces.

The heat dissipation fins 10 and 11 are arranged so that the adjacent heat dissipation fins are arranged perpendicular to each other (at right angles to each other), and the heat dissipation fins 10 and 11 are arranged in a rectangular shape 4 around the LED element 9 Shaped flat plate side surfaces of the heat radiation fins 10 and 11 having large emissivity are oriented in the X direction and the Z direction, respectively. The LED element mounting face 3 and the other back face 4 of the substrate 2 having a large emissivity are oriented in the Y direction.

6, 7, and 8 (5 on the left side of the drawing, 6 on the lower side of the drawing, 7 on the right side of the drawing, and 8 on the left side of the drawing) The upper side of the figure) is also relatively small in area than the above-mentioned surfaces, but is directed in the X and Z directions, and becomes a radiating surface of the heat in these directions. This is because the surfaces (upper surface, both end surfaces) of the respective heat radiating fins 10 and 11 in the thickness direction (thickness direction) are also relatively smaller in area than the flat plate side surface, but the number of surfaces is large, In total, four surfaces in total in each of the X, Y, and Z directions together with the planes, and the planes of irradiation of the heat in these directions are obtained. That is, not only the flat plate-shaped heat radiating surfaces of the front and rear surfaces of the substrate and the heat radiating fin, but also the heat radiating surfaces of the substrate or the heat radiating fin in the plate thickness direction, .

Therefore, among the planar side surfaces of the heat dissipation fins 10 and 11, the radiation surfaces overlap each other on the two facing surfaces of the side on which the LED elements 9 are attached. However, The heat radiation surface of the heat radiation fin does not overlap excessively, and there is no waste of material. The heat from the LED element 9 is transmitted to the rear surface 4 of the substrate 2 through the attachment surface 3 of the substrate 2 and the peripheral side surfaces of the respective heat radiation fins A high heat radiation efficiency can be obtained by a synergistic effect of the formation of a continuous heat transfer surface to be heated and the effect of forming a continuous heat radiation surface that continuously radiates heat from these continuous heat transfer surfaces.

Number of heat dissipation pins:

The number of the heat dissipation fins 10 and the heat dissipation fins 10 and the heat dissipation fins 10 in the left and right sides of FIG. 2 are set to be smaller than the number of the heat dissipation fins 10, 10, or two or more of the upper and lower heat radiating fins 11, 11 of the drawing, and other heat radiating fins are excluded. In this case, the left and right heat dissipation fins 10, 10 of FIG. 2 may be left, or the upper and lower heat dissipation fins 11, 11 of FIG. 2 may be left, It is good to leave each one.

On the other hand, when the number of the plate-like heat-radiating fins is increased, the heat-radiating fin surfaces overlap each other in any one of the three-dimensional directions of X, Y and Z to waste materials, The radiation efficiency (heat radiation efficiency) of the heat is lowered. Therefore, the total number of heat dissipation fins provided on the two front and back surfaces 3 and 4 of the substrate 2 is set to be 8 or less, preferably 2 to 8, in total. However, in the case where the same heat dissipation fins 10 to 17 as shown in Figs. 2 to 10 are left as they are, or only a few or only finely divided and divided in the extending direction of the heat dissipating side, they are regarded as one heat dissipation fin .

The problem in the case where the total number of the heat dissipation fins of the flat plate shape is increased is that the number of fins extending parallel to each other in the same direction as in the conventional example of Fig. (3) on any one side of the heat sink 1 cut at an arbitrary cross section orthogonal to the two sides 3, 4 of the substrate 2 More than one) and too many cases. In the conventional example shown in Fig. 14, there are four pins on the back surface 4 of the substrate 2 extending in parallel directions. In this case, the heat radiation surface of the heat dissipation fin overlaps in any one of the three-dimensional directions of X, Y, and Z, waste of materials occurs, and radiation efficiency of heat is lower than that of occupied space ratio.

3:

3 is not limited to one side of the side (surface side) 3 of the LED element mounting surface (surface side) of the substrate 2 as shown in Fig. 2 but also on the side of the other back surface 4 of the substrate 2 And a heat dissipation fin is further provided. Concretely, in addition to the four flat plate heat-radiating fins 10 and 11 provided on one side of the LED element mounting face 3 of the substrate 2 of Fig. 2, The heat radiating fins 12 and 13 are provided symmetrically with respect to the attaching surface 3 so that the upper limit of the number of the heat radiating fins 12 and 13 is four. The extension lengths (widths) of the heat dissipation fins 10, 11, 12 and 13 on the substrate 2 are determined by the lengths of the sides 5, 6, 7 and 8 of the substrate 2, Respectively.

The heat dissipation fins 12 and 13 provided on the side of the back surface 4 are formed in the same manner as the four heat dissipation fins 10 and 11 provided on the side of the LED element attachment surface 3 of the substrate 2, Symmetrical arrangement in the vertical direction of the drawing. That is, two heat-radiating fins 12, 12 on the left and right sides of the figure, and heat-radiating fins 13, 13 on the upper and lower sides of the figure symmetrically two pieces with the LED element 9 therebetween, And are arranged in parallel to each other. That is, also in the back surface 4 side, the flat plate-like heat dissipation fins 12 and 12 facing each other and the heat dissipation fins 13 and 13 are disposed so as to face each other, Like the heat dissipation fins 11 and 11, between the fins 10 and 10 and the position corresponding to the attachment position of the LED element 9 on the back side. In other words, the heat dissipation fins in a flat plate shape are formed on both sides of the front and back surfaces of the substrate 2 at positions where the LED elements 9 are placed in the middle. The number of the fins extending in the same direction among these heat radiating fins 12 and 13 is set so that the number of fins that extend in the same direction (In any one of the cross sections of the first embodiment).

The heat dissipation fins 12 and 13 are arranged such that the adjacent heat dissipation fins are arranged orthogonally (intersecting at right angles) with respect to the rectangular shape 4 around the position corresponding to the attachment of the LED element 9 on the back surface 4, And each of the flat plate-like side surfaces of the heat radiation fins 12 and 13 having high emissivity faces in the X direction and the Z direction. The LED element mounting face 3 and the other back face 4 of the substrate 2 having a high emissivity are oriented in the Y direction.

In addition, four flat plate heat dissipation plates (not shown) provided on each side 5, 6, 7, 8 of the substrate 2 in the plate thickness direction around the periphery of the substrate 2 and four on the LED device attachment face 3 side of the substrate 2 Not only the surfaces (upper surface and both end surfaces) in the plate thickness direction of the pins 10 and 11 but also the surfaces (lower surface, both end surfaces) in the thickness direction of the heat radiating fins 12 and 13 on the back surface 4 side And becomes a radiation surface of the heat. Each of the heat dissipation fins in the plate thickness direction is comparatively small in area, but the number of planes is twice as large as that of the upper and lower surfaces, the both end surfaces, and in the X, Y, and Z directions And becomes the emitting surface of the heat in the direction of these. That is, not only the flat plate-shaped heat radiating surfaces of the front and rear surfaces of the substrate and the heat radiating fin, but also the heat radiating surfaces of the substrate or the heat radiating fin in the plate thickness direction, .

Therefore, also in the case of Fig. 3, there is no overlapping of the heat-releasing surfaces of the heat-radiating fins in any direction in the three-dimensional directions of X, Y and Z, and there is no waste of material, Radiation efficiency is obtained.

Figures 4, 5 and 6:

The heat dissipation fins of the flat plate shapes of Figs. 4, 5 and 6 are formed on the side of the LED element attachment surface 3 of the substrate 2 and the side of the other back surface 4 of the substrate 2 And the heat dissipation pin of any one of Figs. In the heat sinks shown in Figs. 4, 5 and 6, not only the flat plate-shaped heat radiating surfaces of the front and rear surfaces of the substrate and the heat radiating fin, but also the heat radiating surfaces of the substrate and the heat radiating fin in the plate thickness direction, And has a heat radiating surface facing in any three-dimensional direction of Z.

Fig. 4 is a plan view of the heat dissipation fin of Fig. 3, in which the side of the LED element attachment face 3 of the substrate 2 is divided into three parts, one of the two heat dissipation fins 11, have. In the arrangement of the asymmetric heat radiating fins on the other back surface 4 side and the up and down direction of the drawing, three pieces of the two heat radiating fins 12 are omitted, The heat dissipation fins are provided.

Fig. 5 is a side view of the heat dissipation fin of Fig. 3, in which the side of the LED element attachment face 3 of the substrate 2 is shown with two heat dissipation fins 11, 11 on the upper and lower sides And only two sheets of heat radiating fins 10, 10 on the left and right sides are used. The other side of the back surface 4 is also provided with the heat dissipation fins symmetrically arranged in the vertical direction of the figure with the substrate interposed therebetween and the two upper and lower heat dissipation fins 13, And only two pieces of heat radiating fins 12, 12 on the left and right sides of the drawing are provided, and a total of four heat radiating fins are provided.

Fig. 6 is a plan view of the heat dissipation fin of Fig. 3, in which the side of the LED element attachment face 3 of the substrate 2 is shown with two heat dissipation fins 11, 11 on the upper and lower sides 5 are the same as those in Fig. 5 in that only two sheets of heat radiating fins 10, 10 on the left and right sides are used. The arrangement of the heat dissipation fins asymmetrically in the vertical direction of the drawing with the substrate interposed therebetween is the same as the arrangement of the heat dissipation fins (12, 12) on the left and right sides of the drawing And four heat radiating fins are provided in total.

Figures 7 and 8:

The heat sink 1 for LED lighting shown in Figs. 7 and 8 is made of a thin metal plate having a constant thickness such as aluminum, a substrate 2 (surfaces 3 and 4), a flat heat dissipation fin 10 12) are integrally formed. In the heat sinks shown in Figs. 7 and 8, not only the planar heat radiating surfaces of the front and rear surfaces of the substrate and the heat radiating fin, but also the heat radiating surfaces of the substrate and the heat radiating fin in the plate thickness direction, And has a heat radiating surface facing in any three-dimensional direction.

The number of fins extending parallel to each other and extending in the same direction among the heat dissipation fins 10 to 12 is set to be an arbitrary cross section perpendicular to the two surfaces 3 and 4 of the substrate 2 It is supposed that the number is two or less. That is, the thickness of the heat sink 1 is not more than two at any end face of the heat sink 1 cut in an arbitrary direction orthogonal to the two faces 3 and 4 of the substrate 2. [

In this case, the heat dissipation fins 10 to 12 in the flat plate shape are bent from the end side of the substrate 2 toward the Y direction (up and down direction in the drawing) extending in the direction of the respective surfaces, . 7 shows two heat dissipation fins 10 and 10 and two heat dissipation fins 11 and 11 bent toward the upper side of the drawing in such a manner that they face each other with the LED element 9 interposed therebetween. Fig. 8 shows the pins 11 and 11 facing the upper side in the figure, and the pins 12 and 12 are bent toward the lower side of the figure in the form of facing each other. The arrangement and the number of these flat plate heat dissipation fins 10 to 12 are the same as those in Fig. 2 and Fig. 8, respectively. However, since the heat dissipation fins 10 and 11 bend the end portion of the substrate 2, the arrangement structure located at the end portion of the substrate 2 is different. For example, the extension length (width) of the heat dissipation fins 10 and 11 on the substrate 2 is determined by the length of each side 5, 6, 7, and 8 of the substrate 2 Width) of course.

9 and 10:

As shown in Figs. 7 and 8, the heat sink 1 for LED lighting shown in Figs. 9 and 10 is a thin plate made of a material having a constant thickness such as aluminum, for example, a substrate 2 (surfaces 3 and 4) And the heat dissipation fins 10 to 17 in a flat plate shape are integrally formed. In the heat sinks shown in Figs. 9 and 10, not only the planar heat radiating surfaces of the front and rear surfaces of the substrate and the heat radiating fin, but also the heat radiating surfaces of the substrate and the heat radiating fin in the plate thickness direction, As shown in Fig.

9 is an exploded view of the flat plate shape before molding into the heat sink 1 shown in Fig. 10 and is a plan view showing the angle of the substrate 2 along the boundary line (edge portion) The side edge portions are bent in the three-dimensional directions of X, Y and Z in the figure, and the plate-like heat dissipation fins 10, 11 and 14 to 17 are integrally formed and integrally formed as a material.

10, the two heat dissipation fins 10, 10 facing each other with the LED element 9 therebetween are bent toward the opposite direction of the upper side and the lower side of the drawing. The heat dissipation fins 10 and 10 are formed by two heat dissipation fins 14 and 15 parallel to each other (both sides of the heat dissipation fin 10 and 10) (The heat radiating fins 10 on the right side of the drawing), and two heat radiating fins 16, 17 (the heat radiating fins 10 on the right side of the drawing) parallel to each other. Two pins 11 and 11 facing each other with these LED elements 9 therebetween are bent from both sides of the substrate 2 toward the lower side of the drawing. The extension length (width) of these heat dissipation fins 10 and 11 on the substrate 2 is equal to the length (width) of each side (each side) of the rectangular substrate 2. It can also be said that Fig. 10 shows an example of the shape of the substrate having the stepped portion.

11:

11 shows the LED element 9 mounted (mounted) on the surface 3 of the substrate 2 in a rectangular shape when viewed from the top. Substrates 2 are disposed on two side surfaces (two sides) 5 and 6 intersecting at right angles to each other in the four peripheral sides 5, 6, 7 and 8 of the substrate 2 , And two plate-like heat-radiating surfaces 10 and 11, each of which is a rectangular (rectangular) in plan view, are integrally and continuously formed. 11, assuming that the direction of the flat surface (plane) of the substrate 2 is the Y direction, the plate-like heat radiation surface 10 oriented in the X direction and the plate-like heat radiation surface 11 Is a projected area in two different directions of the plate-shaped heat radiation surface. Therefore, it is a matter of whether or not such a projected area satisfies P? 8 占 S with respect to each cross-sectional area S of the substrate 2, respectively.

The respective lengths (widths) of these plate-like heat-radiating surfaces 10 and 11 in Fig. 11 are respectively equal to the lengths (widths) of the two side surfaces (two sides) 5 and 6 of the substrate 2 And have the same length (width). However, if at least one of these plate-like heat-radiating surfaces 10 and 11 can obtain a specified projection area, either or both of the two side surfaces 5 and 6 of the corresponding substrate 2 May be smaller than the length (width). It is also possible to provide gaps or slits in the same plate-like heat radiation surfaces 10 and 11 in the extending direction of the substrate side surfaces 5 and 6 and to divide the plate-like heat radiation surfaces 10 and 11 into several, (Size) or shape may be changed, and the projected area may be partially changed.

The two plate-like heat radiation surfaces 10 and 11 are provided orthogonally to each other with the substrate 2 (surface 3) at the right angle but not at right angles to each other through an interval (gap) 24 have. However, if at least one of these plate-like heat-radiating surfaces 10 and 11 can obtain a specified projected area, these heat-radiating surfaces (heat-radiating fins) 10 and 11 do not pass through the gap 24, They may be partially interposed, and they may be integrated perpendicularly to each other (continuous). These also apply to the case where plate-like heat radiation surfaces are formed integrally and continuously on the other side surfaces 7 and 8 of the substrate 2.

12:

Fig. 12 shows an LED element 9 mounted (mounted) on a surface 3 of a circular substrate 2 which is a circle (circular plate) or an ellipse in plan view. A cylindrical plate-like heat-radiating surface 12 having the substrate 2 as a top portion is disposed on the entire side surface (four sides) continuous in an arc shape around the substrate 2 as one, Respectively. 12, assuming that the direction of the flat surface (plane) of the substrate 2 is the Y direction, the projected areas P2 and P3 of the two directions, which face each other in the X and Z directions, As shown in FIG. It is a matter of whether or not the projected area P2 directed toward the X direction and the projected area P3 directed toward the Z direction satisfies P > = 8 x S with respect to each cross-sectional area S of the substrate 2. [

Of course, if only a specified projection area can be obtained, only a part of the arc-shaped continuous side surface (side in the thickness direction to the thickness direction) 5, 6, 7, 8 around the periphery of the substrate 2, The shape heat radiation surface 12 may be integrally and continuously formed with the substrate 2 serving as a guide. That is, the plate-like heat radiation surface 12 is not provided on the entire circumference (circumference) of the circumference (circumference) of the substrate 2, and a slit or a gap is provided in the circumferential direction, Any one of the substrate side surfaces 5, 6, 7, and 8 may be partially exposed without partially providing the opening surface 12 in the circumferential direction.

12, the length (width) of the cylindrical plate-like heat-radiating surface 12 provided on the entire circumference (circumference) of the substrate 2 corresponds to the circumference of the substrate 2 naturally. In addition, if the projection area specified by the plate-like radiation surface 12 can be obtained, the divided plate-like radiation surface or the plate-like radiation surface 12, even if it is integral, partially does not satisfy the defined projection area But may be a small projection area. In addition, when the substrate is a triangle, a rectangle, or a polygon as viewed in plan, the plate-like heat dissipating surface 12 also has a triangular, rectangular, or polygonal shape corresponding to the shape. In this regard, Fig. 11 can also be said to be a square shape in which the substrate is provided with plate-shaped heat-radiating surfaces 10 and 11 only on two sides of a quadrangle in plan view.

The heat sink 1 of the present invention is formed by integrally molding a thin metal plate having a constant thickness, such as aluminum, for example, and has a tubular three-dimensional shape as a whole hollow. That is, these heat sinks 1 of the present invention can be manufactured by bending or pressing a thin metal plate so that the substrate 2 and the plate-like heat dissipating surfaces 10 to 12 are integrally and continuously formed Are preferable.

Opening the room:

In the case of the heat sink 1 shown in Figs. 11 to 12, the plate-like heat dissipating surface 10 (see Fig. 10) is formed on one or all of the side surfaces 5, 6, 7, 8 of the substrate 2, To 12 are formed integrally and continuously with the substrate 2 serving as a reference. Therefore, in the substrate 2 and the plate-like heat dissipating surfaces 10 to 12, a continuous heat radiating surface (not shown) disposed in the vicinity of the LED element 9 and oriented in all three directions of three-dimensional X, Y and Z . That is, it has a heat radiating surface facing in any three-dimensional directions of X, Y, and Z.

11 shows a case in which the front and back surfaces 3 and 4 of the substrate 2 facing the Y direction and the front and rear surfaces of the plate-like heat dissipating surfaces 10 and 11 facing in two directions, , And a continuous plate-like heat-radiating surface facing in three directions of X, Y and Z, respectively. 11, the side surfaces 7 and 8 of the substrate 2 in the thickness direction (thickness direction) of the substrate 2 and the side surfaces 7 and 8 of the substrate 2 in the plate- Side surfaces 14 and 15 and the bottom surface 16 in the plate thickness direction (thickness direction) of the plate-shaped heat radiation surface 11 and both side surfaces 17 and 18 in the plate thickness direction (thickness direction) The surface 19 also forms a continuous flat plate-like heat dissipating surface facing in three directions of X, Y and Z. [ The side surface 15 in the thickness direction of the plate-like heat radiation surface 10 and the side surface 15 of the plate-like heat radiation surface 11 are made to be in contact with each other when the gap 30 is interposed between the plate- There is an advantage that the thickness direction side surface 17 can be obtained. As described above, in Fig. 11, not only the flat plate-like heat-radiating surfaces of the front and back surfaces of the substrate or the plate-like radiating surface (radiating fin) but also the heat radiating surfaces in the plate thickness direction of the substrate or plate- Y, and Z, respectively.

In the case of Fig. 12, only one plate-shaped heat-radiating surface 12 is provided. It is to be noted that the plate-like heat radiation surface 12 is formed integrally and circularly (circularly or cylindrically) in a circular shape (continuous in an arc shape) around the periphery of the substrate 2 Respectively. Therefore, also in Fig. 12, the front and back surfaces 3 and 4 of the substrate 2 facing the Y direction, the front and rear surfaces of the plate-like heat dissipating surface 12 facing in the X and Z directions, If there is only a constant thickness in the range of 0.7 to 6 mm, a continuous heat-radiating surface is formed on the bottom surface 20 which is continuous in a circular shape (circular arc) facing in the Y direction. 12 also includes not only the flat plate-shaped heat-radiating surfaces of the front and rear surfaces of the substrate or the plate-shaped heat-radiating surface (heat-radiating fin) but also the respective heat-radiating surfaces of the bottom surface 20 of the plate- X, Y, and Z. In this case, The heat from the LED element 9 is transmitted to the back surface 4 and each of the plate-like heat dissipating surfaces 10 to 12 through the surface (surface) 3 of the substrate 2 on the side where the LED element is attached Thereby forming a continuous heat transfer surface to be heated. Further, a continuous heat-radiating surface for radiating heat successively from these continuous heat-radiating surfaces is formed.

Plate-shaped projection area of the heat release surface:

In the present invention, the plate-shaped heat-radiating surfaces (10 to 12) in two different directions are arranged in a radial direction with respect to each other, Of the substrate cross-sectional area S is 8 times or more, preferably P? 12 占 S, that is, the projected area P is 12 times or more of the corresponding substrate cross-sectional area S Respectively. In other words, if the projected areas P of the plate-shaped heat radiation surfaces in two different directions satisfy the relationship (expression) that P? 8 占 S, preferably P? 12 占 S, It goes without saying that even if there is a plate-shaped heat-radiating surface, there is a part that does not satisfy this relation on the plate-like radiating surface.

(Both of them are both) larger than a certain size so that the projected area P of the plate-shaped heat radiation surfaces in two different directions satisfies the relationship with the substrate cross-sectional area S, It is possible to remarkably improve the heat dissipation efficiency using radiation as a main body. That is, by setting the projected area P to be equal to or larger than the predetermined size, the LED element 9 of the heat sink of the type shown in Figs. 11 to 12 can be used in a closed space with little or no air convection, It is possible to make the heat dissipation of the heat dissipation member as a heat dissipation mainly composed of radiation and to significantly improve the heat dissipation efficiency. In other words, the heat sink having the heat radiating surface facing in any three-dimensional direction of X, Y, and Z in Figs. 11 to 12 has a structure (structure) and a synergy effect of the projected area P, The heat dissipation efficiency of the LED element 9 can be remarkably improved by making the radiation of the LED element 9 in the closed space with or without convection caused by air such as a heater or the like as a main radiation.

On the other hand, in the plate-like heat radiation surfaces 10 to 12, the projected areas P of the plate-like heat radiation surfaces in two different directions do not satisfy this relationship, X S, that is, the projected area P is too small, less than 8 times the corresponding substrate cross-sectional area S, the heat radiation efficiency mainly using radiation can not be improved when the heat sink is used in the closed space. In other words, even if a heat sink having a heat radiating surface facing in any three-dimensional direction of X, Y and Z in Figs. 11 to 12 has a synergistic effect with its shape (structure) The heat dissipation of the LED element 9 in the closed space with no convection caused by the air is made into heat radiation mainly made of radiation, but its heat radiation efficiency can not be improved. As described above, in the case where the heat sink of the type having a heat radiating surface facing in any three-dimensional direction of X, Y, and Z in Figs. 11 to 12 is used in the closed space for an on-vehicle LED lamp or the like , The specific surface area of the heat-radiating surface or the solid-like shape is raised, and the projected area of the plate-like heat-radiating surface largely affects the heat radiation due to radiation.

Here, the projected area P of the plate-shaped heat-radiating surfaces 10 to 12 is a projected area of the plate-shaped heat-radiating surfaces 10 to 12, and is projected by the parallel light irradiated from the direction perpendicular to each plate- Is defined as the projected area P. Is a condition in which the radiation heat is most efficiently generated when the angle of the parallel light to be irradiated is not a right angle direction with respect to each plate-like heat radiation surface but an angle other than the angle. It is not preferable as an index for accurately determining the heat dissipation performance of the plate-shaped heat dissipation surface, without specifying the heat dissipation area when the two heat dissipation surfaces face each other. The projected area defined in this case is a heat dissipating area in the case where the heat transfer surface is the most efficient for radial heat transfer and is suitable as an index that most suitably expresses the influence of the heat dissipation area on the plate heat dissipation surface.

In the present invention, the projected area P of the plate-shaped heat radiation surfaces 10 to 12 is defined as the magnification with respect to the cross-sectional area S of the substrate 2 shown in Figs. 11 to 12. The cross- Passes through the attachment position 9 of the LED element of the substrate 2 (intersects with (9)) as shown by the dotted lines on the substrate 2 of 11 to 12, &Lt; RTI ID = 0.0 > 12 < / RTI >

In Fig. 11, it is assumed that both the projected area P0 of the plate-shaped heat radiation surface 10 and the projected area P of the two plate-shaped heat radiation surfaces in different directions of the projected area P1 of the plate- need. That is to say, the projected area P0 projected by the light irradiated from the direction perpendicular to the plate-like radiation surface 10 becomes the cross-sectional area of the substrate 2 as well as the attachment position of the LED element 9, It is necessary to satisfy P? 8 占 S with respect to the area S0 of the cross-section C0 parallel to the projection plane of the heating face 10. The projected area P1 projected by the light irradiated from the direction perpendicular to the plate-shaped heat radiation surface 11 is a cross-sectional area of the substrate 2, passing along the attachment position of the LED element 9, It is necessary to satisfy P? 8 占 S with respect to the area S1 of the cross section C1 which is parallel to the projection plane of the projection optical system 11.

12, in the case where the substrate is an elliptical shape or a circular arc or an elliptical shape, the projected area P2 on the long diameter side (or the area having a large area) and the short diameter side And the projected area of the bones of the projected area P3 of the plate-shaped radiating surface of the small-size portion (the small portion side) satisfies the requirement. On the contrary, in the case of the full-circle shape, since the projection area in any direction is the same, if the direction of the flat surface (plane) of the substrate 2 is the Y direction, at least two plate shapes Select the opening surface. These two plate-shaped radiating surfaces are plate-shaped radiating surfaces having a projection area P2 directed in the X direction and a projected area P3 projected in the Z direction. It is necessary that the projected areas P2 and P3 of these plate-like heat dissipating surfaces satisfy P? 8 占 S with respect to each cross-sectional area S of the substrate 2, respectively. That is to say, the projected areas P2 and P3 projected by the light emitted from the direction perpendicular to these plate-shaped heat radiation surfaces become the cross-sectional areas of the substrate 2 along the attachment positions of the LED elements 9, It is necessary to satisfy P? 8 占 S with respect to the areas S2 and S3 of the cross-sections C2 and C3 which are parallel to each other.

Principle of heat dissipation, action:

The principle of heat dissipation in the case where the heat sink 1 of the present invention is installed in a space free from air convection to perform LED illumination will be described. The heat (heat flux) Q emitted by the LED element 9 is applied to the LED element attachment face 3 of the substrate 2 by the LED element 9 mounted on the LED element attachment face 3, (Not shown) of the bottom portion of the element 9, as shown in Fig. The heat Q transferred to the LED element attachment face 3 is not only the heat radiation fins 10 and 11 on the attachment face 3 side but also the heat radiation fins 10 and 11 on the back face 4 side, The fins 12 and 13 are also conducted to the above-mentioned respective heat radiating surfaces continuously (without delay), and to almost the same level and higher level. Therefore, heat radiation from the heat radiation surfaces of these fins, particularly by radiation, is equally performed at a certain level or higher, and heat radiation efficiency can be increased.

The heat dissipation fins 10 to 17 are formed such that the number of fins extending in the same direction is equal to or smaller than 2 in any cross section perpendicular to the surfaces 3 and 4 of the substrate 2, Or less, and do not overlap with each other excessively in the same direction. Accordingly, the conducted heat Q is directed in the three-dimensional directions of X, Y, and Z, and the heat of the mounting surface 3 and the back surface 4 of the substrate 2, the angle of the heat radiating fins 10 to 17 From the surface of the heat radiating surface to the surrounding closed space (heat radiating space), respectively. Therefore, the heat emitted by the LED element 9 is radiated at a high radiation efficiency, which is a radiation amount higher than a certain degree, in any three-dimensional X, Y, and Z directions. This is because the heat sink 1 of the present invention has a smaller number of heat dissipation fins 10 to 17 and a higher heat dissipation efficiency than that of the heat dissipation fin 10 to 17 even in a closed heat dissipation space , And each projected area in any direction of the directions of X, Y, and Z is large. The heat sink (1) of the present invention has a simple structure with a small number of heat dissipation fins (10 to 17), and excellent heat dissipation efficiency per unit area of heat dissipation.

Here, in the case where the housing for illuminating the vehicle is to radiate heat by radiation required in a narrow space or in a closed space, the X, Y and Z axis directions 3 Dimensional direction) is influenced by the size of the projected area, and the larger the projected area, the higher the radiation efficiency of heat.

14, the projection area in the Y direction is the sum of the plane of the base plate 30 and the plane of the upper side of the fin 40. Therefore, the overlapping of the fin portions 40 There is no waste of material, and the projected area is large. However, since the projected area in the Z direction is the sum of the side surface of the substrate portion 30 and the side surface of the fin portion 40, The height becomes a small area which is less than 50% of the total surface area. The projected area in the X direction is the sum of the front surface of the substrate portion 30 and the front surface of the fin portion 40. Even though there are four pieces of the fin portion 40, for example, And there is a lot of material waste, and the radiation efficiency of heat per a heat radiation area is low. That is, in the X direction, a plurality of fins overlap to occupy space, but the projected area is smaller and the radiation efficiency of heat is lower than that of a large occupied space. Or, the number of the X-direction pins is excessively large, and the waste of the material is large due to the excessive pin, and the weight becomes heavy.

In other words, in the heat sink H of the conventional example shown in Fig. 14, the radiation efficiency of heat in any one of the X, Y, and Z axial directions (three-dimensional directions) is necessarily lowered. As a result, the radiation efficiency of heat in any one direction in the three-dimensional direction can not be increased, so that the radiation efficiency of the overall heat is low. In addition, the number of pins in the X-direction or the like is excessive and waste of material is large. That is, common to these prior arts is that there is no waste of material in any three-dimensional direction of the heat sink, and the heat sink can not be used as a heat sink having a high radiation efficiency compared with a small occupied space.

In addition, this point is also the same in the above-described Patent Document 5. In the direction in which the radiating portions of the U-shaped scoop portions are overlapped in a large number, the radiant efficiency of heat is low and the three- The waste heat of the material in the X direction is large. In addition, the width of the slit-like opening portion is severely restricted in order to secure the size of the heat sink itself or the area of the heat dissipating portion, and thus the width is inevitably narrow. Therefore, when applied in a closed space, The improvement of the heat radiation efficiency by the heat sink can not be expected.

13:

The heat sink 25 shown in Fig. 13 shows a comparative example. Only one plate-shaped heat-radiating surface 13 is provided on one side surface of the substrate and no matter how wide the projected area of the plate- , The heat radiation due to radiation becomes insufficient.

13, an LED element 9 is attached to a surface 3 of a quadrangular (rectangular) substrate 2 in a plan view, and the side surfaces 5, 6, 7, 8 of the substrate 2 And one plate-like heat-radiating surface 13 is integrally formed and continuously formed on the side surface 5 of the base plate 2 as the top. In other words, as compared with the case of the invention example of Fig. 11, except for the absence of the plate-like heat-radiating surface 11 of the side surface 6 of the substrate 2,

In the case of Fig. 13, the plate-shaped heat-radiating surface on the side surface of the substrate is only the plate-shaped radiating surface 13 of the substrate side surface 5, and the top and bottom surfaces 3 and 4 of the substrate 2 facing in the Y- , A continuous plate-like heat-radiating surface facing in two directions, X and Y, is formed on the top and bottom surfaces of the plate-like radiating surface 13 facing in the X direction. 7 and 8 of the substrate 2 in the thickness direction (thickness direction) of the substrate 2 and the thickness direction of the plate-like heat radiation surface 13 (thickness direction) of the substrate 2 And both the side surfaces 21 and 22 and the bottom surface 23 in the thickness direction also form a heat dissipation surface. The projection area P4 of the plate-shaped heat radiation surface 13 satisfies P? 8 占 S with respect to the cross-sectional area S4 of the sectional area C4 of the substrate 2.

However, the heat radiating surface in the Z direction in Fig. 13 is formed on the both side surfaces 6 in the thickness direction (thickness direction) of the substrate 2 and in the thickness direction (thickness direction) of the plate type heat radiation surface 13 21 and 22, and there is no flat plate-shaped heat dissipation surface. As a result, there is a limit to increase the projected area P5 of the heat radiation surface facing the Z direction, which is the side surface 6, 21 and 22, and the projected area P5 can not be P? Therefore, even if the projection area in the X direction is satisfied by the projection area P4 of the plate-like radiation surface 13, the projection area of the radiation surface in the Z direction becomes insufficient. Therefore, at least two Plate-like heat dissipating surfaces can not satisfy P? 8 占 S, respectively. Because of this, the heat radiation due to the radiation of the heat radiation surface in the Z direction is small, so that the radiation heat radiation property as a whole is not exhibited.

LED power consumption:

Although the heat sink 1 of the present invention has an excellent heat radiation effect, if the power consumption of the LED 9 as a heat source becomes large, the heat radiation performance may be insufficient even if the heat radiation effect is excellent. Therefore, as a preferable application range of the present invention, the power consumption of the LED 9 is 20 W or less, which is a very suitable range. In the case where a plurality of LEDs 9 with relatively low power consumption are attached, a range in which the sum of the power consumption of the plurality of LEDs is 20 W or less is a very suitable condition.

Material:

The heat sink (1) of the present invention does not increase the number of heat radiating surfaces without complicating the shape and structure of the heat sink, and conversely, simplifies the structure and reduces the number of heat radiating surfaces Can be achieved. As a result, it is possible to select various material materials, a manufacturing method, or a manufacturing process, and to provide a heat sink easy to manufacture at low cost. In this respect, the material and the material can be various materials such as aluminum (pure aluminum), aluminum alloy, copper (pure copper), copper alloy, steel plate, resin and ceramic, A pressing process, a bending process, a die casting process, a casting process, a forging process, an extrusion process, or a manufacturing process.

Aluminum or aluminum alloy:

Aluminum (pure aluminum) or an aluminum alloy is preferably used as a material having strength, rigidity, light resistance, corrosion resistance, thermal conductivity, thermal conductivity, heat resistance and workability, which are necessary characteristics as the heat sink 1. Aluminum (pure aluminum) or aluminum alloy is preferably 1000-series pure aluminum such as 1050, which is particularly large in thermal conductivity and heat dissipation characteristics required for a heat sink and specified in AA to JIS standards.

The heat sink according to the present invention is optimum in a use (installation) environment in which heat radiation due to convection of air can hardly be expected in a use (installation) state in which a surrounding heat radiation space is closed and a volume is small and air convection hardly occurs . In such a use environment, in order to dissipate heat, it is necessary to center heat radiation by radiation, and in the conventional heat sink structure in which convection of air is made to be the main heat radiation performance by increase of the surface area of a heat- Heat radiation due to radiation is insufficient, and efficient heat radiation as a whole can not be achieved. On the other hand, the heat sink according to the present invention is a heat sink most suitable for use (installation) environment in which heat is radiated by radiation of heat from the heat radiating side of the heat radiating side or the like and heat radiation due to air convection is hardly expected, Can be said.

In addition, since the heat dissipation surfaces including the LED element attachment face 3 and the heat dissipation fin are integrally structured so as not to pass the joint face therebetween, contact heat resistance which is generated in the case of bonding them separately is generated Do not. Therefore, the heat conduction between the LED element mounting face 3 and each of the heat dissipating faces is facilitated, and as a result, the heat radiation performance of the heat sink as a whole becomes remarkably high. Further, the structure of the heat sink 1 is high in rigidity because it is a structure in which the heat radiating fins are oriented in three directions of X, Y and Z directions. Therefore, even in the case of receiving vibration in a vehicle-mounted lamp or the like, the shape can be maintained without using a special reinforcing member, and maintenance-free and high-speed operation can be achieved.

Common to the embodiments:

As described above, depending on the use and the attachment site of the heat sink 1, the space for mounting the components and the space for mounting the heat sink 1 can be provided on the respective heat radiating surfaces of the mounting surface 3, back surface 4, A slit, a partial shape, or the like may be provided on a part of each of these surfaces by three-dimensional molding processing in which such a surface is notched, or irregularities or steps are provided. Alternatively, the heat-radiating side may be partially omitted or changed in shape depending on necessity of component attachment or the like.

The heat sink 1 of the present invention does not increase the number of the heat dissipation fins and simplifies the structure without complicating the shape and structure of the heat sink, particularly the shape and structure of the heat dissipation fin , And reducing the number of heat dissipation fins. As a result, it is possible to select various material materials, manufacturing methods, or manufacturing processes, and to provide a heat sink easy to manufacture at low cost.

(aluminum)

Aluminum (pure aluminum) or an aluminum alloy is preferably used as a material having both strength, rigidity, light weight, corrosion resistance, thermal conductivity, heat radiation property and workability, which are necessary characteristics as the heat sink 1. Aluminum (pure aluminum) or an aluminum alloy is preferably 1000-series pure aluminum such as 1050 which is particularly large in heat conduction characteristics required for a heat sink and specified in AA to JIS standards.

(Mounting on vehicle-mounted lamp)

Mounting of the heat sink according to the present invention in a vehicle-mounted LED lamp or the like can be carried out in the same manner as mounting of a heat sink, which has been heretofore used, and this is an advantage. In general, a vehicle-mounted LED lamp (vehicle lamp) includes an LED substrate on which an LED element as a light source is mounted, a reflector that reflects light from the LED toward the front in the light irradiation direction, a housing surrounding the LED substrate and the reflector, An outer lens made of a transparent material that closes the open front of the housing, and a heat sink arranged in thermal contact with the LED substrate. The reflector is formed of a resin material and has a reflecting surface of a reflecting surface having a focal point near the LED on the LED substrate. Here, the heat sink of the present invention is used as a heat sink arranged in thermal contact with the LED substrate or the LED substrate.

In this respect, the heat sink according to the present invention can also be applied to, for example, the vehicle-mounted LED lamp of Fig. 15 described above, in which the LED device of the present invention is mounted on the mount plate 57 as the lamp unit 55 The mounted substrate 2 can be mounted and assembled as a heat sink. However, even in this case, the heat sink according to the present invention is an on-vehicle LED lamp, which is not a main body of radiation due to convection caused by heat transfer to surrounding air such as a conventional heat sink, .

[Example]

In the heat sinks of FIGS. 2, 3, 7, and 14, the heat sinks in the drawings are actually manufactured by changing the projected areas in various ways. Then, an LED element was mounted (mounted), and after an electric current was applied to the LED element, the average temperature (° C) of the LED element at the normal time was measured. These results are shown in Table 1.

In all of the examples, the projection areas of the heat sinks in the same drawing (same shape) were changed by changing the height in the Y direction of the flat plate side surfaces of the rectangular heat dissipation fins. At this time, the shape and the size of the heat sink in the same drawing (same shape) as seen from the plane of the substrate 2 were made equal to each other. In each example, the plate thicknesses of the substrate 2 and the heat radiation fins were made equal to each other. The calculation of the thermal resistance value R was carried out according to the above-described method or formula.

Each of the heat sinks shown in Figs. 2, 3, and 14 was manufactured by machining such as an extruded bar of 1050-series aluminum of the JIS of the material or a cutting process. The heat sink shown in Fig. 7 was manufactured by press-forming an end portion of a 1050-series aluminum cold-rolled sheet of JIS with a heat-dissipating fin. The heat conductivity λ of each of the heat sinks of FIGS. 2, 3 and 14 is 230 W / (m · K), the heat sink of FIG. 7 is 231 W / (m · K), and is 120 W / (m · K) or more.

In all the examples, the size of the rectangular shape of the substrate 2 was 100 mm (Z direction) x 100 mm (X direction) x plate thickness 2 mm. 2, 3, and 7, the distance between the parallel heat radiating fins 10, 10 on the right and left sides, and 11 and 11 on the upper and lower sides was 80 mm or more (the distance from the center of the LED element was 35 mm or more). The distance between adjacent heat-radiating fins 40 in Fig. 14 is 10 mm. Further, the radiating fins have a rectangular shape, and the length in the X direction or the Z direction of the flat plate side surface is 70 mm, the height in the Y direction of the flat plate side surface is changed in the range of 35 to 80 mm, The projected area of the heat release surface was changed.

In each of the examples, a commercially available black cationic resin film was electrodeposited on the surface. The surface emissivity epsilon of the heat sink (substrate and heat-radiating fin) at this time was measured with the commercially available portable emissivity measuring device. In each example, the heat dissipation fins 10 to 17 had common heat- The same was 0.83.

In all of the examples, a commercially available LED element having a power consumption of 13 W was mounted on the substrate, and then a current of 3.7 V, 0.85 A was applied from a direct current power source to emit the LED element. At this time, while observing the temperature of the LED element with a thermocouple, the heat sink was sealed in a wooden (wooden) cylinder of 300 mm x 300 mm x 300 mm simulating a closed space without air convection of the vehicle-mounted LED lamp . Then, the ambient temperature around the heat sink was simulated to simulate the closed space of the LED lamp mounted on the vehicle, and light was emitted in an indoor atmosphere at 20 占 폚. Then, the temperature of the steady state was measured without rising or falling after a predetermined time elapsed. The measurement was carried out five times in each example, and the average temperature was obtained and evaluated as the average temperature (캜) at the normal time.

As shown in Table 1, Examples 1, 2, 5, 6, 9 and 10 of FIGS. 2, 3, and 7, which are heat sinks of preferable shapes, and the surface emissivity? of the substrate and the plate-like heat dissipating surface is not less than 0.80. Thereafter, the plate thicknesses of the heat sinks are 2.0 mm within the specified range of 0.9 to 6 mm, respectively, and the total projected areas of the respective heat radiation surfaces of the heat sink are within the specified ranges of 19000 to 60000 mm 2.

As a result, even in a closed space without air convection simulating the in-vehicle LED lamp, the temperature of the LED element at the normal time is set to the extremely low temperature . The thermal resistance value R is 4.0 K / W or less. Therefore, it was confirmed that these examples had excellent heat radiation performance (cooling performance) by heat radiation.

On the other hand, in Comparative Examples 3, 7 and 11, the thermal conductivity? Is not less than 120 W / (m 占,), the surface emissivity? Is not less than 0.80, Is 2.0 mm, which is within the specified range of 0.8 to 6 mm. However, the total projected area of each heat dissipation surface of the heat sink is less than 1900 mm < 2 >

As a result, in the heat sinks of these comparative examples, the temperature of the LED element at the normal time is 100 ° C or less, which is the allowable temperature, but is commonly higher than that of the above-described example, and the heat resistance value R of the heat sink is 4.0K / W Over. Therefore, in these comparative examples, the heat radiation performance (cooling performance) due to heat radiation is remarkably poor in the closed space without air convection, as in the case of an in-vehicle LED lamp.

In Comparative Examples 4, 8, and 12, the heat radiation rate? Is not less than 120 W / (m 占 λ), the surface emissivity? Is not less than 0.80, The total projected area of each of the heat dissipation surfaces of the heat dissipating unit is within a specified range of 19000 mm2 or more. However, the thickness of the heat sink is 0.77 mm which is too thin beyond the specified range of 0.8 to 6 mm.

For this reason, even in the heat sinks of these comparative examples, the temperature of the LED element at the normal time is 100 ° C or less, which is the allowable temperature, but is commonly higher than the above-described example, and the heat resistance value R of the heat sink exceeds 4.0K / W have. Accordingly, in these comparative examples, the heat radiation performance (cooling performance) by the radiation of heat is remarkably poor in the closed space without air convection as in the case of the in-vehicle LED lamp.

In the heat sinks of Comparative Examples 13 and 14, the shape of Fig. 14 is deviated from the preferred form. Therefore, in Comparative Example 13 in which the total projected area of each heat radiation surface of the heat sink is less than 19000 mm < 2 >, the temperature of the LED element at normal time is 100 DEG C or lower, which is an allowable temperature, The heat resistance value R of the sink exceeds 4.0K / W. In Comparative Example 14, the total projected areas of the respective heat radiation surfaces of the heat sink are within the range of 19000 to 60000 mm 2 respectively, and the temperature of the LED element at the normal time is 100 ° C or lower, which is the allowable temperature. , And the heat resistance value R of the heat sink exceeds 4.0 K / W. Therefore, in Comparative Examples 13 and 14, heat radiation performance (cooling performance) due to heat radiation is poor in a closed space without air convection, such as an in-vehicle LED lamp.

11, 12, and 13, the projected area of the plate-like heat-radiating surface is varied in various ways and actually manufactured. In the closed space in which the vehicle-mounted LED lamp is simulated, And the temperature of the LED element was measured. Table 2 shows the evaluation results of the heat radiation performance by radiation of such heat.

The change in the projected area of each plate-like heat-radiating surface of each heat sink was made by changing only the area of the rectangular plate-like radiating surfaces 10 to 12 = the size (height in the Y-direction). The shape and size of the substrate 2 and the plate thickness of the substrate 2 and the heat dissipating surfaces 10 to 12 were both equal to 2.0 mm and the thermal conductivity λ was also 210 W / (m · K) in common. The size of the rectangular shape (in plan view) of the substrate 2 shown in Figs. 11 and 13 is commonly 100 mm (Z direction) x 100 mm (X direction) (In plan view) as the substrate 2.

Each of the heat sinks shown in Figs. 11 and 13 was manufactured by press-forming an end portion of a 1050-series aluminum cold-rolled sheet of JIS into a plate-like heat dissipating surface, and a heat sink of Fig. Pressed.

In each of the examples, a commercially available black cationic resin film was electrodeposited on the surface. The surface emissivity at this time is measured with a commercially available portable emissivity measuring apparatus developed by Japan Aerospace Exploration & Production Agency. In each example, the heat dissipation surfaces of the substrate 2 and the plate-like heat dissipation surfaces 10 to 12 are common Lt; / RTI >

Further, in all of the examples, a commercially available LED element was mounted on a substrate, and then a current (3.145 W) of 3.7 V, 0.85 A was applied from a direct current power source to emit the LED element. At this time, while observing the temperature of the LED element with a thermocouple, the heat sink was sealed in a wooden cylinder of 300 mm x 300 mm x 300 mm simulating a closed space without air convection of the vehicle-mounted LED lamp. Then, the ambient temperature around the heat sink was simulated to simulate the closed space of the LED lamp mounted on the vehicle, and light was emitted in an indoor atmosphere at 20 占 폚. Then, the temperature of the steady state was measured without rising or falling after a predetermined time elapsed. The measurement was carried out five times in each example, and the average temperature thereof was evaluated.

As shown in Table 2, the heat sinks 21, 22, 24 and 25 of FIGS. 11 and 12, which are heat sinks of preferred shapes, have a thermal conductivity λ of 120 W / (m · K ), And the surface emissivity? Of the substrate and the plate-like heat dissipating surface is not less than 0.65. Thereafter, the thickness of the heat sink is 2.0 mm, which is within the specified range of 0.7 to 6 mm, and the projected areas P0, P1 (unit mm < 2 >) in the two different directions of the plate- All or P2 and P3 (unit mm < 2 >) satisfy P > 8 x S, respectively.

As a result, even in a closed space without air convection simulating a vehicle-mounted LED lamp, the temperature of the LED element at the normal time is set to a temperature not higher than 42 deg. C It can be kept at a low temperature. Therefore, it was confirmed that these examples had excellent heat radiation performance (cooling performance) by heat radiation.

On the contrary, Comparative Examples 23 and 26 are FIGS. 11 and 12, which are heat sinks of preferable shapes, wherein the thermal conductivity λ is 120 W / (m · K) or more, the surface emissivity ε is 0.65 or more, And the sheet thickness is 2.0 mm, which is within the specified range of 0.7 to 6 mm. However, in Comparative Example 23, all the projected areas P0 and P1 (unit mm < 2 >) of the plate-like heat radiation surface and P2 and P3 (unit mm & It is too small. Therefore, the projection areas P of the plate-like heat radiation surfaces 10 to 11 in two different directions can not satisfy P? 8 占 S, respectively.

13, the projected area P4 (unit mm < 2 >) of the plate-shaped heat radiation surface 13 toward the X direction satisfies P 8 x S, , The projected area P5 (unit mm < 2 >) of 22, 22 does not satisfy P &ge; 8 x S, and the heat radiation performance by radiating the radiation surface in the Z direction is insufficient. Therefore, the projected area P of the plate-like heat radiation surface 12 in two different directions can not satisfy P? 8 占 S, respectively.

As a result, in the heat sinks of these comparative examples, the temperature of the LED element at the normal temperature was 100 DEG C or lower, which is the allowable temperature, but it was higher than that in the above-described example, and in the closed space without air convection simulating the LED lamp mounted on the vehicle , The heat radiation performance (cooling performance) due to heat radiation is poor.

These series of tests do not take into consideration the engine or heat exchanger assumed at the time of mounting on an actual vehicle, the heat input from various electric devices, the heat input by direct sunlight, and the like. Therefore, it is considered that the temperature of the LED element is lower than the temperature of the LED element in the actual vehicle mounted LED (actual vehicle mounted LED). In other words, although the actual use environment of the vehicle-mounted LED becomes stricter, these series of tests have sufficient precision and reproducibility as a comparison of the performance of the heat sink, and the performance of the above- .

From the above facts, it is found that the structure of the heat sink according to the present invention, the thermal conductivity?, The surface emissivity?, The thickness of the heat sink, the total projected area of the respective heat radiating surfaces, The critical efficiency of the heat radiation efficiency mainly based on radiation is proved. In addition, the number of the heat dissipation fins also supports the significance of the preferable arrangement of the heat dissipation fins.

(Industrial availability)

As described above, the heat sink according to the present invention mainly radiates heat by radiating heat from the radiating side surface of the radiating side surface or the like, and further, the heat radiating efficiency of the radiating main body can be remarkably improved. Therefore, it is an optimal heat sink for a narrow use space (use and installation environment) in which there is almost no air convection. In addition, it is possible to provide a heat sink having a minimized use amount of the material aluminum or aluminum alloy, making it possible to downsize and thin the heat sink, high degree of freedom of design, and low manufacturing cost.

Therefore, it can be used for heat-radiating parts for automobile lighting fixtures such as vehicle-mounted LED lamps, cooling boxes for cooling of inverters and various electric devices.

Further, by using the heat resistance value R of the heat sink, it is possible to obtain the total projected area of the board and the plate-like heat dissipation plane and the required plate thickness of the heat dissipation plane, so that the design of the heat sink becomes easy . Therefore, it can be used as a design method of a heat sink in which radiation efficiency is radically improved.

1: Heatsink
2: substrate
3: LED element mounting surface of the substrate
4: back side of substrate
5, 6, 7, 8: plate thickness direction side of the substrate
9: LED element
(Or the plate-shaped heat dissipating surface of the heat-radiating fin), the heat-radiating fins (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22,
P: Projected area of the plate-shaped heat dissipating surface
C: Cross section of substrate
S: sectional area of section C

Claims

An LED device is attached to either one of front and back surfaces of a substrate and a plate-like heat radiation surface is formed integrally and continuously with the LED device attachment surface around the LED device. Wherein the heat sink is made of aluminum or an aluminum alloy having a thermal conductivity? Of 120 W / (m 占 K) or more, and a surface emissivity? Of the substrate and the plate-
Wherein the thickness of the substrate and the plate-shaped heat-radiating surface is set to a range of 0.8 to 6 mm, and then the thickness of each projected area of three planes perpendicular to each other in the three- The sum of which is in the range of 19000 to 60000㎟
And a heat sink for LED lighting.

The method according to claim 1,
Wherein the aluminum or aluminum alloy has a thermal conductivity? Of 140 W / (m 占 K) or more, a surface emissivity? Of the substrate and the plate-like heat dissipating surface is not less than 0.83, and a thickness of the substrate and the plate- 8 to 4.0 mm, and the total projected area of the heat sink is set to 19000 to 50000 mm < 2 >
Heatsink for LED lighting.

3. The method according to claim 1 or 2,
The difference ΔT between the normal temperature T at the time of light emission and the ambient temperature T0 around the heat sink is divided by the power consumption W of the LED element T-T0) / W is 4.0K / W or less
Heatsink for LED lighting.

3. The method according to claim 1 or 2,
The number of the heat dissipation fins extending in the same direction of the heat dissipation fins is larger than the number of the heat dissipation fins of the heat dissipation fins on the front and back surfaces of the substrate In an arbitrary cross section orthogonal to one surface,
Heatsink for LED lighting.

A heat sink for LED lighting, which has a plate-like heat dissipating surface at the top of the substrate integrally and continuously on the side of the substrate on which the LED element is mounted,
The projected area of the plate-like heat radiation surface in two different directions is the projected area P projected by the parallel light emitted from the direction perpendicular to the plate-like heat radiation surface, And satisfies P? 8 占 S with respect to each cross-sectional area S of the substrate which is a cross section parallel to the projection plane
And a heat sink for LED lighting.

6. The method of claim 5,
And having a heat radiating surface facing in any three-dimensional direction by the substrate and the plate-
Heatsink for LED lighting.

The method according to claim 5 or 6,
Wherein the substrate is rectangular in plan view and the plate-like heat dissipating surface is formed by more than one side of the square
Heatsink for LED lighting.

The method according to claim 5 or 6,
Wherein the substrate is circular in plan view and the plate-shaped heat-radiating surface is formed in a tubular shape on part or all of the sides of the circular plate
Heatsink for LED lighting.

The method according to claim 5 or 6,
Wherein the substrate and the plate-like heat dissipation surface are made of aluminum or an aluminum alloy having a heat conductivity? Of 120 W / (mK) or more, and the surface emissivity? Of the substrate and the plate- The plate thickness of the shape heat radiation surface is set in the range of 0.7 to 6 mm
Heatsink for LED lighting.

The method according to any one of claims 1, 2, 5, and 6,
Wherein the heat sink is a heat sink for a vehicle-mounted LED lamp
Heatsink for LED lighting.